Polymer of hexafluoropropylene oxide is a known material. If end groups are removed from a hexafluoropropylene oxide polymer comprising only carbon, fluorine and oxygen, it becomes superior in thermal stability, antioxidation, mechanical stability, anticorrosive property, etc. The hexafluoropropylene oxide polymer can be used even at extremely low or high temperature, and is widely used in vacuum pumps, automobiles, memory hard disks for storing information, high-performance diluents for the use in aerospace engineering, due to its lubricative durability. Its application has been also expanded into various areas such as greases, release agents, liquids with a relatively low refractive index and oils. In particular, researches have been performed on how to prevent reflection by using an end-function-modified polymer with a weight average molecular weight of 400-1,000. Applicability of a polymer with a weight average molecular weight of 2,000-6,000 to an anti-fingerprint agent is also under study.
U.S. Pat. Nos. 3,412,148 and 3,322,826 disclose processes of preparing polymers of hexafluoropropylene oxide. In these processes, an anionic initiator is prepared and hexafluoropropylene is used as a diluent. As a result, hexafluoropropylene oxide is polymerized into a polymer with a weight average molecular weight of about 5,500. For using hexafluoropropylene as a diluent, reaction should be conducted at an extremely low temperature such as −30° C. or lower. A recent study reports the results of research activities using various polar solvents and under various reaction temperatures [Macromolecules, 2009, 42 (3), 612-619].
However, there has been no research report regarding a process of polymerizing hexafluoropropylene oxide by directly using hexafluoropropyl oligomer.